The present disclosure is directed to electrically controlled pneumatic (ECP) brake systems and more specifically to a semi-active mode of the system between the active mode and the inactive mode.
The present method manages ECP equipped trains in situational environments where unrequested train stoppage due to detection of on-board equipment failure negatively impacts overall railroad operations. Understanding that trains are a component of a larger overall system operation which covers territory from departure to final destination there is a need to isolate the standard mainline operational requirements and enable specialized local operational requirements specific to the local railroad yard and or facilities.
The present method allows an ECP train to transition to and from main line operation from and to yard operation where only a subset of the overall functional control is required. In such situations, the system control capability will provide an increase in performance reliability based on the operating conditions of a given zone and or operation constraint.
With the advent of ECP train brake control for main line operation, many rail yard and siding operational conditions warrant specialized train handling techniques. For example, coal and or ore trains pass through automated loading and unloading facilities. In these situations, the train control is managed either manually or through automated means which may be located on-board or off-board the train. During the automated loading and or unloading process, the train is moved through the loading or unloading facility by constant tractive effort with the train brake released. In the occurrence of an undesired train brake application, the loading and or unloading process would be interrupted. This interruption would be costly in regard to the lost time to stop and restart the loading or unloading process.
The ECP train-lined network operating within this environment brings a new dilemma to this process and the train system. ECP systems have the intelligence to automatically initiate a train stoppage upon the detection of critical ECP system events. These events, although mandatory for mainline operation, may not be relevant for loading, unloading or yard operation, and as a result, create a hindrance to railroad operation where train stoppages are not desirable.
Although the loading and unloading operation has been used as an example of the benefit of this patent, other non-mainline operating scenarios can also benefit from this method.
Current methods for moving ECP trains through loading and unloading facilities include:                Manually releasing the train brake and mechanically indexing the railroad cars through the loading/unloading facility;        Set train to conventional operation and control train by locomotive brake only;        Control the train through the loading/unloading facility with standard ECP brake control and allowing the ECP system to automatically stop the train upon detection of critical system events.        
The current American Association of Railroads (AAR) ECP specifications and as a result, current technologies require the ECP system to be either completely active or completely inactive. As a result, if it is desirable to disable ECP for a brief train movement, the ECP system must be re-initialized as the make-up and geometry of the train information is lost in the inactive state. This present method of ECP train brake control allows the ECP system to be placed in a semi-active state where full operational control of the ECP devices on the cars is disabled, and then when desired, the system can be transitioned back to the original state without having to be re-initialized.
The present method operates an ECP brake system, which include a system controller and ECP devices on a train, in a semi-active mode between an active mode and an in active mode. The method includes setting the system controller to the semi-active mode if the ECP brake command is release; and setting the released ECP devices to the inactive state by the system controller when entering the semi-active mode. The ECP devices are set to an active state and to apply the brake by the system controller in response to an ECP brake command of apply. The ECP devices are reset to release and then to the inactive state by the system controller in response to an ECP brake command of release.
The system controller determines if a critical event has occurred for the electrically controlled pneumatic brake system, and if so, the system controller also sets a pneumatic brake system to apply in response to an ECP brake command of apply. The system controller sets the pneumatic brake system to an emergency apply state in response to an ECP brake command of apply if a critical event has occurred. The system controller maintains the electrically controlled pneumatic brake system and the pneumatic brake system applied in response to an ECP release command if the critical event is still present.
In the semi-active state, the system controller maintains power on a train-line to the ECP devices and monitors train-line integrity.